[Pulmonary artery: angiographic technique optimization with magnetic resonance].

The authors optimized the Magnetic Resonance Angiography (MRA) technique for the study of the different portions of the pulmonary artery-i.e., the common trunk, right and left main arteries and the lobar, segmental and subsegmental branches. Twenty volunteers were examined with MRA of the pulmonary arteries with a 1-T superconductive magnet (Impact) and the time-of-flight (TOF) technique. The volunteers were divided into two groups by age (ranges: 20-40 and 41-70 years). The trunk and main branches were studied with the 2D TOF technique, while 2D TOF images were compared with 3D TOF images in the study of peripheral (lobar, segmental and subsegmental) branches. The images were processed with the maximum intensity projection (MIP). In the statistical comparison between 2D and 3D TOF images, the t-test was used (p < 0.05). The 2D TOF images acquired on the sagittal oblique and coronal planes, with presaturation pulses, permitted optimal depiction of the trunk and of the right and left branches in all the volunteers. Both 2D and 3D TOF images yielded excellent images in the study of the lobar branches. In the volunteers under 40 years of age, 3D TOF sequences visualized the peripheral (segmental and subsegmental) vessels better than 2D TOF sequences (451 vs. 361); the difference was statistically significant. In the volunteers over 41 years of age, the ratio was reversed: 467 for 2D TOF vs. 362 for 3D TOF sequences; again, the difference was statistically significant. The correct integration of 2D and 3D TOF sequences, according to the different segments of the pulmonary artery and to patients' age, permitted the complete and accurate visualization of the pulmonary arteries with MRA.